Steam-engine valve



4 Sheets-Sheet 1. E. PILKINGTON. STEAM ENGINE VALVE.

(No Model.)

Fumo-mnu., wAsumlrrau, D, c.

(No Model.) .4 Sheets-Sheet 2. F. PILKINGTON. STEAM ENGINE VALVE.

No. 437.618. Patented Sept. 30, 1890.v

......... 57% @met e,

4 Sheets-Sheet 3. P. PI NGTON. STEAM NE VALVE.

(No Model.)

Patented sept. so', 1890.

Il A W.. y, l M W W 0 y 4 Sheets-Sheet 4.

Padzented Sept. 30, 17,890..

P. 'PIL-KINGTON. STEAM ENGINE VALVE.

m tlrolllfllfll IIIIIIIID 4 .Iliff (No Model.)

UNITED f STATES PATENT OFFICE.

FRANKLIN PILKINGTON, OF ANNISTON, ALABAMA.

' STEAM-ENGINE VALVE.

' sPE'cIFIoATIoN forming part of Letters Patent No. 437,618, datedseptember 3 0, 1890.

Application filed December 26, 1888. Serial No.4 294,585. (No model.)

To all whom if may concern.-

Be it known that I, FRANKLIN PILKINGTON,

a citizen of the United States, residing at Anniston,in the county ofCalhoun and State of Alabama, have invented certain new and usefulImprovementsin Steam-EngineValves; and I do declare the following to bea full,

clear, and exact description of the invention,

such as will enable others skilled in the art Vto which it appertains tomake and use the and has for its object to improve the ends ofcylinders, the main valves, their location, openings in and through samefor compression in andbalancing, the back valve-seats and openings forcompression in same, the stuffing-box in back valve-seat at crank end,the hollow wedges for adjusting the back valveseat to valve and methodfor expanding them before starting the engine, and the cap on on line 10of Fig. 6.

of valve on line y y, Fig. 1. Iview of the valve at back or head end ofcylsteam-chest at ends of cylinder.

The improvement consists inthe details of construction and the novelcombin ation of the parts, which will be hereinafter more fullydescribed and claimed, and which are shown in the annexed drawings, inwhich- Figure 1 is a vertical longitudinal section through center ofcylinder about on the line 1 1 of Fig. 2. Fig. 2 is a horizontal sectionabout on the line 2 2 of Fig. 1. vertical cross-section on the throughline :t of Fig. 1. Fig. 4 is a vertical cross-section on the line 'y yof Fig. 1 Fig. 5 is a vertical cross-section on the line ,z ,z ofFig. 1. Fig. 6 is a face view of the back valve-seat next to valve atcrank end. Fig. 7 is a rear view of the said back valve-seat at crankend. Fig. S is a cross-section of the back valve-seat on the line 8 8 ofFig. 6. Fig. 9 is a longitudinal section on an enlarged scale of thehollow wedge for adjusting the back valve-seat to the valve.` Fig. 10 isan edge view of back valve-seat and side view ofthe hollow wedge Fig. 11is a face View Fig. 12 is a face inder on line e' z, Fig. 1. Fig. 13 isa detail view of the curved rocker around the exhaust- Fig. 3 is a pipeto drive the valves on line w tu, Fig.r1. Fig. 14 is a detail view ofthe ends of rocker, Fig. 13. Fig. 15 is the bearing for rocker, shown indotted lines fu c, Fig. 1.

A D D is a cut-0H valve. It is a plain twin `vvalve of ordinaryconstruction and is placed to one side of center of steam-chest, so"that the rocker which drives it will not come over the center ofcross-head.

E is a cap over the twin valve. It is oblique at the sides near eachend, as indicated by the dotted lines a4 in Fig. 1, thereby making asteam-tight joint across top of cylinder. `The wedges F (the two beingprovided for each end of the cylinder, one located at each side of thevalves and the valve-seats, as

shown most clearly in Fig. 2) are made hollow and connect by pipe frombleeder at throttle-valve to elbow f at bottom of wedge,

Fig. 3, the water and steam, from steam-pipe passing in Wedge at bottom,thence up and over'top of cylinder, thence down the wedge on the otherside, as shown `by arrows, Fig. 3,

thence by pipe from elbow f, Fig. 3, to eX- haust-pipe, therebyexpanding the wedges before the engine is started, so the'valves cannotbind by getting hot iirst at top and center.

G are coil-springs interposed between the ends of the cylinder and thebalance-plates C, which are provided at each end of the cylinder to holdsaid balance-plates against the hollow wedges F when the throttle isshut and the engine is stopping. At all other times the pressure on therear side of said valve-seats is equal to or greater on the back thanthe pressure on the front side thereof.

I-I is a steam-chest; h, steam-ports; I, exhaust-chamber incylinder-casting, and l exhaust-ports in lower ends of the valves B. Thelower end bar of the valves is strengthened by the rib b, Fig. 3, whichin\Fig. 1 ob structs the View of the said exhaust-ports I.

la is the piston-rod stuffing-box in theend of cylinder andbalance-plate, Figs. 1, 2, and 7, and is designed to prevent steamescaping near the piston-rod either externally or` through thebalance-plate into cylinder. The iiange Z on the end of thecylinder-head pro- IOO jecting into the balance-plate forms part of P,cut-oif-valve stem to rocker, Figs. 3 and 4; p, rods connecting theparts of the twin cutoff valve D D together, Figs. 1 and 5; q, openingsin valve and valve-seat at `the crank end of the cylinder' forpiston-rod to pass through, Figs. 1, 3, and 11; fr and fr passages invalves and valve-seats for compression space, Figs. 1, 3, 4, 6, 8, l1,and 12; s, openings through valve B at head end of cylinder forbalancing the said valve.

The hole q in the valve B at the crank end of the cylinder is suhcientlylarge for the piston-rod to pass through and at the same time admit thecylinder-pressure at all times back of the said valve, thereby balancingthe same. The valves B B and their connection are so disposed withreference `to each other vand the rocker that they balance themselves onthe rocker and take up all lost motion or looseness in rocker-joints andvalve-stem connections,` thereby allowing plain pin-joints-`non-adjustable-to be used. The openings through the valves for balancingand the piston-rod, act as auxiliary ports both for admission andexhaust. The main valves B B control admission, exhaust, andcompression, and

they could with slight variation be adapted to a sin gle-valve engine.The hollow Wedges are held by nuts F at top and bottom of cylinder. (SeeFig. 3.) The main valves also act as a safety-valve for cylinder, inthat they do not Viillthe space by one-eighth of an inch to cylnext tovalves one-sixteenth of an inch, the

same area as end of cylinder, which is counterbored three-eighths of aninch deep to allow reboring `without interfering with the `valves. Theimprovement by this arrangement is this: The valves being virtually inthe cylinder and the edge of the counterbore and end and edge of valvesacting as edges of ports, the width of port-opening being made by valvetravel, there are no ports to be filled and emptied at each stroke ofthe piston, and as a result the ordinary port area is done away with andthe clearance or waste room made that much less, `and as a result theengine would use less steam for a given amount of work, and, if acondensing-engine, the condenser would have ,that much less volume tocondense, and on that account taking less water or increasing thevacuum, or both. The said passages fr, r', and r are for the purpose ofincreasing the compression-space when the exhaust closes to produce theproper cushion for the rotating parts-piston head and rod, cross-head,and connecting rod. For seventy tive revolutions per minute or less theywould not be needed.

, The operation of the engine is as follows:

the cylinder, the passages r being always open to cylinder by passagesr, Figs. 3, 11, and 12, sliding down over passage fr, Figs. 4, 6, and 8,thereby opening the passages r in Figs. 1, 3, and 8 to compression, andthey remain open during admission and expansion and close holding theterminal pressure-that is, the pressure in cylinder just before theexhaustopens-by the valve sliding up and bringing passage r, Figs. 3,11, and 12, above passage r, Figs. 4, 6, and 8, just before the exhaustopens. VThere is a cavity in Fig. 12 same as fr, Fig. 3, (not shown inFig. 12,) as it is the face and not the center of valve. The cavities r,Figs. 1, 3, and 8, remain closed, holding the inclosed pressure duringall the time the exhaust is open, so that they are not subject toexhaust at all. Then as the valve slides down and closes the exhaust thecavities are again opened to receive compression,

and so the process continues at each revolu- Y tion, getting the benetof large compression without exhausting from compression-space. The areaof the cavities being drawn in about one per cent. of pistondisplacement, the clearance in counterbore and between piston head andvalve and in openings through and back of valve would be about one percent.,which would give two per cent. for compression and one per cent.subject to exhaust, thereby sav'- ing one per cent. of the steamadmitted to the cylinder at terminal pressure,if this one per cent. incavities was in steam andexhaust ports, and getting just as smoothrunning engine.

In engines for electric lighting, where the clearance is usually aboutten percent., the clearance by this valve would be about two to threeper cent. and thel cavities would be made to hold any amount desired forsmooth running-if necessary seven to eight per cent.-therebysaving thatmuch at each stroke of the piston. 1f the space in cavities was madeless and the exhaust to close later, there would then be a saving due toearlier cut-od and IOO IIO

lower terminal pressure; so it will be a saving over present practiceeither Way. In this increases the clearance by increasing the thicknessof valve to get exhaust-openings, and theclearance only increases bymakingthe openings for piston-rod and balancing longer. Thus, in examplebefore us, doubling the capacity of valve would increase the clearanceat valve any desired increase of port area only crank end three inchesby 'four inches by one or ninety-six plus sixty-four equals one hundredand sixty cubic inches, or one and sevenninths per cent., in place ofone-fifth of one per cent., or eight times as much. In the examplebefore us the piston is at quarterstroke, the valves full open forsteam, and exhaust cut-olf justclosed. The cavities r are placed in thetop end of valve and valve-seat, so as to drain themselves of condensedsteam, so as not to wait for re-evaporation to empty them forcompression.

The stuiiing-box bolts O, Fig. 1, for the valve-rods b are made longenough to set in engine-base stands and act as guides to stuif-` ing-boxgland and valve-stem b. The gland can thus be screwed up while theengine is running without getting the wrench in the way of the rocker,Fig. 13, or w w, Fig. 1. The stuffing-boxes are made upside down to beconvenient for packing.

There is a separate casting a at each end of cylinder inclosing hollowwedges, balanceplate, and valve at bottom and sides for convenience inmaking, and the bolt for connecting cylinder to cylinder-head goesthrough this casting, as shown in Figs. 3 and 4.

The balance-plate is made thick, so as not to spring with the fullpressure against it during exhaust when there is no pressure against itnext to cylinder. The pin-holes w in Figs. 13 and 14 are slotted to getthe pins in or out after the valve-stem b is in place. The valverods bat each end of cylinder and the exhaust-pipe I are in the same straightline, and the rocker W, for operating the valves, is deliected midway ofits ends at fw to extend around the said exhaust-pipe, as shown mostclearly in Fig. 13. The bearing V, in which the short shaft V isjournaled, is mounted at its ends on the bases V2, in which the lowerends of the bolts O are stepped.

Having thus described my invention, what I claim, and desire to secureby Letters Patent,

1. In an engine, the combination of the cylinder having steam-chests andsteam inlet and exhaust ports at each end and the caps closing the topsof the steam-chests and ex-y tending to or against the cylinder-headsand having oblique edges, substantially as and for the purposedescribed.

2. In a steam-engine, the combination, with the cylinder, the frontvalve, and the balanceplate, of the cylinder-head having an innerflange, as l, to lit into the said plate, substantally as and for thepurpose described.

3. In a steam-engine, the combination of the cylinder,the front valve,the balanceplate, the cylinder-head, and the packing k, extending acrossthe joint between the plate and cylinder-head and fitting in each,substantially as and for the purpose described.

4. The combination, with the cylinder and the valve working in the endthereof, of the balance-plate placed between the cylinderhead and thevalve, and the springs arranged between the said plate and thecylinder-head, substantially as and for the purpose described.

5. The combination, with the cylinder having cavities r and passages fr,of the valves having corresponding passages r, substantially as andfor'the purpose described.

6. The combination, with the cylinder and the valve, of thebalance-plate having a reit, substantially as and for the purposedescribed.

S. The combination, with the cylinder, the valve, and the plate, of thewedges interposed between the end of the cylinder and the valveseat andhaving steam-passages through them, substantially as and for the purposedescribed.

9. The combination, with the cylinder and the valve, of the hollowwedge, the steampipe extending from the lends of the wedge and havingthreaded portions, andthe nuts mounted on the threaded portions of thesaid pipes for adjusting the wedge, substantially as described.

10. The combination, with the steam-cylinder, the valves at its ends,and the exhaustpipe between its ends, the valve-stems and theexhaust-pipe .being in a straight line, of the rocker connected at itsends with the valve-stems and having its middle portion deflected toextend around the said exhaustpipe, substantially as described.

11. The combination of the cylinder, the valVe,-the valve-stem, the bed,the stuffingbox, the stufling-box gland, and the set-screws having theirlower ends stepped in the bed and having their upper ends journaled inthe cylinder and passing through the said gland, substantially asdescribed.

In testimony whereof I affix my signature in presence of two witnesses.

FRANKLIN PILKINGTON.

Vitnesses:

D. D. McLEoD, R. H. ROBERTS.

Vloo

IIO

